Human Blood Composition and Tests

Blood Composition

• Blood is a fluid connective tissue
• Plasma is the non-living fluid matrix
• Formed elements are the living blood cells
• Erythrocytes (red blood cells) are the most numerous formed element
• Leukocytes (white blood cells) are crucial for immunity
• Platelets are cell fragments important for blood clotting

Major Components of Whole Blood

• Whole blood is withdrawn and placed in a tube
• Centrifuging separates the components
• Plasma makes up 55% of whole blood, the least dense component
• Buffy coat contains leukocytes and platelets (less than 1%)
• Erythrocytes make up 45% of whole blood, the most dense component

Blood Tests

• Hematocrit measures the percentage of red blood cells in blood.
• Normal hematocrit values differ between males and females.
• Lower RBC count can indicate anemia.
• Anemia is a condition where cells are not able to divide properly due to a lack of vitamin B12.
• RECTAL CANCER could potentially be triggered by a microscopic deficiency of vitamin B12.

Blood Plasma Composition

• Plasma is mostly water (~90%)
• Over 100 dissolved solutes (nutrients, gases, hormones, wastes, proteins, inorganic ions)
• Plasma proteins are the most abundant solutes
• Proteins produced primarily by the liver.
• Albumin is the most abundant protein, maintaining plasma osmotic pressure.

Plasma Proteins

• Albumin: 60% of plasma proteins, key for osmotic pressure and transport
• Globulins (alpha, beta, gamma): transport proteins (36%), involved in immune response and transport of lipids and vitamins.
• Fibrinogen: 4% of plasma proteins, essential for blood clotting.

Formed Elements

• Composed of complete cells (WBCs) and cell fragments (platelets)
• RBCs lack nuclei and organelles
• Most formed elements survive in blood for few days and do not divide.
• All are made in bone marrow.
• Important cells for immunity and defense against diseases.
• Leukocytes (WBCs) make up less than 1% of whole blood
• There are different types of Leukocytes, each with specific functions
• Crucial for immunity and defense
• Function in defense against diseases and chronic infections.
• Granulocytes: visible granules (neutrophils, eosinophils, basophils)
• Agranulocytes: no visible granules (lymphocytes, monocytes)

Erythrocytes (Red Blood Cells)

• Specialized for gas transport
• Packed with hemoglobin
• Biconcave shape for maximizing surface area for oxygen uptake
• Anucleated and lack most organelles, maximizing space for hemoglobin
• Normal values differ between males and females

Anemia

• Abnormally low oxygen-carrying capacity of blood.
• Causes include blood loss, decreased RBC production, or increased RBC destruction
• Three main types of anemia based on cause: blood loss, low RBC production, high RBC destruction

Explore the essential components and characteristics of human blood in this quiz. Learn about plasma, formed elements, and the significance of blood tests like hematocrit. Understand how these factors contribute to overall health and potential medical conditions.